arch/arm/mach-rockchip/rk_timer.c

   1 /*
   2  * (C) Copyright 2015 Rockchip Electronics Co., Ltd
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <asm/arch/timer.h>
   9 #include <asm/io.h>
  10 #include <linux/types.h>
  11
  12 struct rk_timer * const timer_ptr = (void *)CONFIG_SYS_TIMER_BASE;
  13
  14 static uint64_t rockchip_get_ticks(void)
  15 {
  16         uint64_t timebase_h, timebase_l;
  17
  18         timebase_l = readl(&timer_ptr->timer_curr_value0);
  19         timebase_h = readl(&timer_ptr->timer_curr_value1);
  20
  21         return timebase_h << 32 | timebase_l;
  22 }
  23
  24 static uint64_t usec_to_tick(unsigned int usec)
  25 {
  26         uint64_t tick = usec;
  27         tick *= CONFIG_SYS_TIMER_RATE / (1000 * 1000);
  28         return tick;
  29 }
  30
  31 void rockchip_udelay(unsigned int usec)
  32 {
  33         uint64_t tmp;
  34
  35         /* get timestamp */
  36         tmp = rockchip_get_ticks() + usec_to_tick(usec);
  37
  38         /* loop till event */
  39         while (rockchip_get_ticks() < tmp+1)
  40                 ;
  41 }
  42
  43 void rockchip_timer_init(void)
  44 {
  45         writel(0xffffffff, &timer_ptr->timer_load_count0);
  46         writel(0xffffffff, &timer_ptr->timer_load_count1);
  47         writel(1, &timer_ptr->timer_ctrl_reg);
  48 }